Preoperative echocardiography identifies symptomatic patients with aortic regurgitation (AR) at risk of late postoperative death from congestive heart failure (CHF); the at risk patients manifest left ventricular (LV) systolic dysfunction (fractional shortening less than 25% or LV end-systolic dimension (LVSD) greater than 55 mm). In this study we found LVSD is also a valuable parameter in evaluating asymptomatic patients with AR, as it is the most sensitive parameter for distinguishing those who will develop symptoms and require operation within 3 year period from those who wiill remain asymptomatic. Specifically, patients with LVSD less than 50 mm are a low risk group and can safely be followed with yearly echoes. Those with LVSD greater than 55 mm have an 80% chance of developing symptoms requiring operation, and are then at high risk of late postoperative CHF. Hence, operation should be considered in patients with LVSD greater than 55 mm even in the absence of symptoms.